Dropping ball... Negative or Zero Work?

[axp107]

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Is it just negative work?

What about.. a positive charge moving along its electric field... negative work also?

Whats Zero Work.. when is Zero work done in physics

 

[aanihc]

Is it just negative work?

What about.. a positive charge moving along its electric field... negative work also?

Whats Zero Work.. when is Zero work done in physics

dropping ball = negative work
positive charge moving along its electric field = negative work

electron traveling around the nucleus = zero work
this is because the force (electrostatic) and direction of travel are always perpendicular to each other.

remember, work = Fdcos(theta). cos(90 degrees) = 0, so it's zero work.

 

[axp107]

dropping ball = negative work
positive charge moving along its electric field = negative work

electron traveling around the nucleus = zero work
this is because the force (electrostatic) and direction of travel are always perpendicular to each other.

remember, work = Fdcos(theta). cos(90 degrees) = 0, so it's zero work.

good call. I was thinking something similar.. planets revolving around the earth.

 

[RoadRunner17]

That's known as the idea of equipotential lines.

 

[swifteagle43]

Is it just negative work?

What about.. a positive charge moving along its electric field... negative work also?

Whats Zero Work.. when is Zero work done in physics

it is bad to think of work in negative and positive. think of it as work done and work released.... ball drop is work released...charge moving is work being done....and yes it carries a negative charge

 

[slyloxy]

dropping a ball= I think this should be positive
remember w= f * d ( both vectors) the force is in this case is the force due to gravity which points downwards and d ( displacement) also points downward since it is moving towards the earth. the two vectors point in the same direction and hence positive work remember theta is zero in this case

For a positive charge moving along the electric field i think should be positive also. remember the electric field and displacement of the charge both point in the same direction.

the electron will be negative work the electric force on the electron due to the electric field and the displacement point in opposite directions and hence negative work.

 

[riceman04]

dropping a ball= I think this should be positive
remember w= f * d ( both vectors) the force is in this case is the force due to gravity which points downwards and d ( displacement) also points downward since it is moving towards the earth. the two vectors point in the same direction and hence positive work remember theta is zero in this case

For a positive charge moving along the electric field i think should be positive also. remember the electric field and displacement of the charge both point in the same direction.

the electron will be negative work the electric force on the electron due to the electric field and the displacement point in opposite directions and hence negative work.

you should specify...it is positive work done by gravity!!!!
but neg work done by the othe side